1. Field of the Invention
The present invention relates to an accumulator fuel injection device provided with a pressure control valve controlling a fuel pressure in the accumulator by moving an armature in an armature chamber and by adjusting escaped volumes of the fuel from the accumulator using a valving element formed integrally with the armature in a control chamber introducing the fuel in the accumulator.
2. Related Art
Conventionally, there are well-known accumulator fuel injection devices of an engine, comprising a supply pump, an accumulator storing highly-pressurized fuels pumped from the supply pump and an injector injecting the fuels supplied from the accumulator (for example, see JP2006-83821). These accumulator fuel injection devices were provided in the accumulator thereof with pressure sensors so as to detect the fuel pressures in the accumulator and solenoid valves so as to escape the fuels from the accumulator.
The solenoid valves are constructed so that they can reduce the fuel pressures in the accumulator by moving the armature in an armature chamber and by adjusting escaped volumes of the fuels from the accumulator using a valving element formed integrally with an armature in a control chamber introducing the fuels in the accumulator. The switching of the solenoid valves are controlled based on detected values of the fuel pressures by the pressure sensors, thereby keeping the fuel pressures in the accumulator to the given pressures.
However, in the conventional accumulator fuel injection devices, when the pressures in the accumulator are largely varied, they are approximately directly transmitted from the accumulator to the pressure control valves, thereby largely varying pressures of valve seats of the pressure control valves. The pressures of the control chamber and the armature chamber are not equalized in the pressure control valve, so that sometimes the valving element was not accurately controlled using the armature. Accordingly, operation of the pressure control valve was unstable.